1. Field of the Invention
This invention relates to a developing device used in an image forming apparatus using an electrophotographic method or an electrostatic recording method, such as a copier, a printer or the like, for forming a visual image by providing an electrostatic latent image formed on an image bearing member with a developer, and to a cartridge for supplying the apparatus with a developer.
2. Description of the Related Art
Since a developer within a developer receptacle provided in a developing device of such an image forming apparatus is consumed in accordance with the proceeding of image forming processes, it is necessary to replenish the developer appropriately. In general, the developer is replenished by supplying it from a developer supply cartridge to a developer receptacle.
For example, as described in U.S. Pat. No. 4,981,218, a developer supply cartridge is mounted in a developing device. In this state, the developer is supplied from an opening provided in the cartridge to a developer receptacle in the developing device. After the supply of the developer has been completed, the cartridge is immediately removed from the developing device.
However, the above-described conventional approach has the following problems:
(1) Even if the developer exceeding the permissible amount of the developer receptable for the developer has been supplied and the developer still remains in the developer supply cartridge, the developer supply cartridge can be detached from the developing device. PA1 (2) The developer supply cartridge can be detached from the developing device even while the developer is supplied.
Hence, the operator may in some cases detach the developer supply cartridge from the developing device even if the developer still remains in the developer supply cartridge. As a result, particles of the developer remaining within the developer supply cartridge are scattered, thereby contaminating the inside or the neighborhood of the image forming device.